Overall program structure

When looking at the overall program structure, we need to look at how entire programs are organized and put together, as well as the lightning rod question of how much nesting is in your language. It almost seems like an afterthought, but how and where will the source code in programs begin executing? In languages based on C, execution starts from a main() function, while in scripting languages, the source code is executed as it is read in, so there is no need for a main() function to start the ball rolling.Program structure also raises the basic question of whether a whole program must be translated and run together, or if different packages, classes, or functions can be separately compiled and then linked and/or loaded together for a program to run. A language inventor can dodge a lot of implementation complexity by either building things into the language (if it is built-in, there is no need to figure out linking), requiring the whole program's source...